The fast-developing field of compliant hydrodynamic fluid bearings has seen more and more acceptance by the art for many applications. These bearings are very low cost and provide excellent low friction characteristics and extremely long life in ultra high speed applications. They are superior to conventional ball bearings and sleeve bearings in many applications, but recent research has identified certain technical improvements which can be made to broaden their implementation.
Many compliant hydrodynamic journal bearings are unidirectional; that is, they must be used with a shaft rotation in only one direction. This requires that the assembly of the bearing be done with some care to assure that the bearing be oriented correctly. It also makes these bearings unsuitable for bidirectional shaft rotation applications.
Prior art attempts to develop a bidirectional journal bearing have suffered from instability and/or loss of load carrying capacity. I believe this has occured because these designs have failed to provide sufficient freedom of movement of the bearing sheet to enable it to flex and conform to the shaft.
Another improvement which I believe could be made to compliant hydrodynamic fluid bearings is a reduction in their start-up torque. Because the bearing sheet is free, it tends to wrap around the shaft. The start-up torque is somewhat higher than that of conventional bearings, and the shaft can be rotated only in one direction. These improvements should contribute to making these bearings more suitable to a broader range of applications than presently exists, and should facilitate an accelerated acceptance by the art of these bearings.